<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <script>
        <!-- 传入非pormise对象 -->
        let p1 = Promise.resolve(521);
        console.log(p1)
        <!-- 传入pormise对象 -->
        let p2 = Promise.resolve(new Promise((resolve, reject)=>{
            resolve(521)
        }))
        console.log(p2)
        <!-- 传入pormise对象 -->
        let p3 = Promise.resolve(new Promise((resolve, reject)=>{
            reject('err')
        }))
        console.log(p3)
        p3.catch(reason=>{

        })
    </script>
</body>
</html>